Rotary piston machine



Oct. 26, 1965 J. KEYLWERT ROTARY PISTON MACHINE Filed April 1. 1963 Fig. 7

United States Patent 3,213,837 RGTARY PISTON MACHINE Johann Keylwert, Cologne-Kalli, Germany, assignor to Kloclrner-Humboldt-Dentz Alstiengesellschaft, Cologne, Germany Filed Apr. 1, 1963, Ser. No. 269,685

Claims priority, application Germany, Apr. 2, 1962,

K 46,351 1 Claim. (Cl. 123-8) The present invention relates to a rotary piston machine, especially rotary piston or circular piston internal combustion engine in which the circumferential surface of the piston is provided with ridges by means of which in cooperation with the inner surface of the enveloping body the working chambers of the machine are sealed relative to each other. The invention more specifically concerns a rotary piston machine of the above mentioned type in which the said ridges and also the end faces of the piston are equipped with sealing strips which together form the sealing system of the machine for the gases in the working chambers. With a machine of the above mentioned type, the machine shaft is, at both sides of the piston, surrounded by a seal which prevents the entry of lubricant from the bearings of the machine shaft into the gap between the end faces of the piston and the side walls of the machine.

After attempts over a period of years, it has only recently been made possible to operate a so-called circular piston machine as gasoline engine. This circular piston internal combustion engine operates with outer mixture formation by means of a carburetor for gasifying the fuel. With heretofore known circular piston machines, the inner confining surface of the enveloping body has the contour of an epitrochoid with two axis-near zones. The piston, the contour of which is designed in conformity with the inner enveloping curve of this epitrochoid, has three ridges by means of which the working chambers of the machine are sealed relative to each other, said working chambers being formed by the inner confining surface of the enveloping body and the circumferential surface of the piston. Said ridges are provided with grooves for receiving sealing strips which improve the sealing of the working chambers relative to each other.

With heretofore known circular piston internal combustion engines, the lubrication is effected by admixing oil to the fuel as is customary with two-stroke cycle piston engines with mixture lubrication. If it is desired to operate a rotary piston internal combustion engine with inner mixture formation, for instance in conformity with the diesel method, the heretofore known mixture lubrication cannot be employed. It would be possible to lubricate the running surfaces in the manner customary with large diesel engine, however, this would not assure the lubrication of all sealing strips.

It is, therefore, an object of the present invention to provide a lubricating system which will assure lubrication of all vital parts to be lubricated.

It is another object of the present invention to provide a lubricating system which will assure that the sealing strips at the ridges and also the lateral sealing strips will be adequately lubricated.

These and other objects and advantages of the invention will appear more clearly from the following specification in connection with the accompanying drawing, in which:

FIG. 1 illustrates a portion of a vertical longitudinal section through the upper part of a circular piston internal combustion engine operated with inner mixture formation.

FIGURE 2 is a view of the piston of the circular pis- Patented Oct. 26, 1965 ton internal combustion engine of FIG. 1 as viewed along line IIII of FIG. 1.

The present invention is characterized primarily by a lubricant supply system according to which lubricant conveying means extend through the lateral wall or walls of the enveloping body and feed lubricant into the gap between said side walls and the respective adjacent end face of the piston, the arrangement being such that in spite of the eccentric movement of the piston the Inbricant will be received in said gap at a portion between the outer gas seal at the end faces of the piston and the inner oil seal at the end faces of the piston, which inner oil seals seal relative to the eccentric shaft. The oil supply is effected through special oil feeding bores in the side walls of the machine.

It will be appreciated that the thus introduced lubricant will, in view of the centrifugal effect, move in the direction toward the above mentioned outer gas seals of the piston near the circumferential surface of the piston. Furthermore, as mentioned above, the ridges are provided with grooves in which additional sealing strips are mounted. Therefore, the lubricant on the radially inwardl directed side of the outer gas seals also passes into the grooves at said ridges. A control of the lubrication for the sealing system of the working chambers of the machine can easily be obtained by effecting the oil supply in an intermittent manner.

It is a fact that generally the sealing strips in the grooves of said ridges are subjected to higher thermic stresses than the sealing strips adjacent the end faces of the piston. Therefore, it may be advantageous to feed lubricant directly into the grooves of said ridges for the sealing strips therein. To this end, the end face or end faces of the piston may be provided with an annular groove which r registers with an oil supply bore in the side walls of the machine.

Referring more specifically to the drawing, the arrangement shown therein comprises a rotary piston 1 eccentrically rotatably arranged within the outer or enveloping body 2 which latter is provided with side walls 3 laterally confining the piston 1. The inner confining surface 4 of the envoleping body 2 has a contour corresponding to an epitrochoid wit-h two axis-near zones. The piston 1 is, in conformity with the inner confining surface of the housing or enveloping body 2, provided with three ridges 5 having grooves 6 therein for receiving sealing strips 7. Interposed between the sealing strips and the bottom of the grooves are springs 8 which continuously urge the sealing strips against the inner confining surface 4 of the enveloping body 2. Within the range of groove 6 there is provided a so-called sealing bolt 9 for interconnecting the individual parts of the entire sealing system of the piston. More specifically, such sealing bolts may be pro vided with corresponding grooves receiving the respective adjacent ends of the sealing strips 7 at the ridges 5 and the sealing strips 10 at the end faces of the piston.

The circular piston internal combustion engine according to the invention is characterized in particular by the fact that the grooves 6 communicate with oil supply bores 11 which originate at the lateral annular groove 12. The annular groove 12 receives lubricant through a bore 13 adapted to be connected to a lubricant supply source and extending through the side wall 3 of the outer body of the machine. The lateral annular groove 12 is located between the outer gas seal 10 and the inner seal 14 which seals relative to the eccentric shaft (not shown) of the machine.

It is, of course, to be uderstood that the present invention is, by no means, limited to the particular arrangement shown in the drawing but also comprises any modifications within the scope of the appended claim. Thus,

3 while the drawing shows the oil supply means 11, 12 and 13 on one side of the machine only, it may also be provided on both sides thereof.

What I claim is:

A rotary piston machine, especially an internal combustion engine having an outer body with spaced side wall members adapted for receiving and journalling an eccentric shaft extending through said side wall portions, a polygonal piston adapted for being rotatably jou-rnalled on the eccentric of said shaft, said piston having axial edges provided with axial grooves, radialseals in the form of sealing strips arranged in grooves, radially spaced seals at the end faces of said piston engaging said side wall members, an annular groove in at least one end face of the piston and concentrically arranged between the said radially spaced seals, a passage leading from said annular groove to each said axial groove, a lubricating supply passage leading thnough -a side wall member adjacent said annular groove, said annular groove extending radially over such a region that the said lubricant supply passage communicates with said annular groove during a portion only of the rotary movement of said piston, said supply passage thus being adaptedduring a continuous supply of lubricant thereto to effect intermittent supply of lubricant to said axial groove.

References Cited by the Examiner UNITED STATES PATENTS 3,033,180 5/62 Bentele 1238 3,065,707 11/62 Ziskal 230-207 X FOREIGN PATENTS 647,709 8/62 Canada.

LAURENCE V. EFNER, Primary Examiner.

JOSEPH H. BRANSON, IR., Examiner. 

